Telegraphic transmitter.



H. J. MAHONY.

TELEGRAPHIC TRANSMITTER.

APPLICATION FILED APR. 10, 1915.

Patent-ed May 1, 1917.

' 3 SHEETS-SHEET I INVENTOR. f/zfMa flan g ATTORNEY. 5.

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H. J. MAHONY.

TELEGRAPHIC TRANSMITTER.

APPLICATION HLED APR. 10, I915.

1 ,224, 187., Patented May 1, 1917.

3 SHEETSSHEET 2- INVENTOR. .zf/l/afi any x 5 I v ATTORNEY.

H. J. MAHONY.

TELEGRAPHIC TRANSMITTER.

APPLICATION FILED APR. 10, 1915.

1,224,187.. Patented May 1,1917.

3 SHEETS-SHEET 3.

13 A TTORNE Y. 5

WE %TE% TELEGBAPILIIC TRANSMITTER.

Specification of Letters Patent.

Patented May 1, 1917.

Application filed April 10, 1915. Serial No. 20,535.

To all whom it may concern:

Be it known that I, HENRY J. MAHONY, a citizen of the United States of America, residing at Green Bay, in the county of Brown and State of WVisconsin, have invented certain new and useful Improvements in Tele graphic Transmitters, of which the following is a specification, reference being had therein to the accompanying drawing.

This invention relates to telegraphic transmitters, especially closed transmitters which employ a neutrally disposed key, and has for its object the production of a simple and efficient transmitter instrument employed in connection with telegraphy, whereby when said neutrally disposed key is moved to the right by the right hand, a series of dots will automatically be produced, the number of dots so made, depending upon the duration in which the neutrally disposed key is held in electrical contact with the automatic dot mechanism. The neutrally disposed key is further adapted to produce a series of dashes when moved to the left by the right hand, and it should be understood that by means of the present device a very simple and efficient instrument has been produced for greatly decreasing the strain in the transmitting of messages.

It should be understood that the speed of the ordinary Morse instrument is limited to the rapidity with which the hand of the operator can move the key, seldom exceeding the average of thirty words per minute when four and six tenths letters to the word is the basis of calculation.

In a steady grind of fifteen thousand words or more, such as press operators often have to undergo at one time, the number of vertical movements made by the hand and wrist is enormous, for the reason that there is required many separatetmovements for each letter on the old Morse key now commonly in use. It is, of course, obvious that any such strain tends eventually to a breakdown known as telegraphers cramps and, therefore, the present invention is especially advantageous for not only increasing the speed at which a message may be sent, but also greatly relieving the strain from the op ator.

One of the principal objects of the present invention is the production of a telegraphic transmitter, wherein the operator may adjust the device instantly to any desired speed or intensity of the dots desired. It should be further understood that the present invention also has for its object the production of an instrument which may be used either by a right hand or left hand operator by merely inverting the receptacle or box which carries the telegraphic transmitter.

In the drawings V Figure l is a top plan view of the transmitting mechanism.

Fig. 2 is a side elevation thereof.

Fig. 3 is a perspective view of the mechanism looking at the rear thereof.

Fig. 4 is a perspective view of the pendulum showing the contact points and plates cooperating therewith.

Fig. 5 is a top plan View of the key showing the contact screws and springs for automatically holding the key in a neutral position.

Fig. 6 is a side elevation thereof.

Fig. 7 is a fragmentary perspective View of the magnet spools showing the insulator positioned within the core of the spools.

Fig. 8 is a perspective view of the boX which contains the mechanism and one dry cell.

Fig. 9 is a diagrammatic view of the circuit connections with the local battery for operating the pendulum in sending automatic dots.

Fig. 10 is a diagrammatic view showing the main line circuit used in connection with the present invention.

By referring to the drawings it will be seen that 1 designates the insulated base or slab upon which the transmitting mechanism is mounted. A pair of vertically disposed magnets 2 are placed upon the insulated base 1 as clearly illustrated in Fig. 3 of the drawings, and have their forward ends resting in a supporting member 3, which supporting member 3 is rigidly connected to a block or swivel plate i. A screw 5 passes through the block 4 and is secured into the base 1, and this block or pivot plate is pivotally mounted upon this'screw A pin 6 extends upwardly from the base 1, and upon this pin 6 the pendulum 7 is mounted in perfect balance for horizontal movement. An insulated armature plate 8 is secured to the pendulum block 7 and adjacent the rear ends of the cores 9 of the magnet spools 2. A balance plate or arm 7 projects horizontally from the upper end of the pendulum block? and constitutes a counterbalance for keeping the pendulum block 7 in perfect balance upon the pin 6.

A retractile spring 10 has one end thereof fastened to the pin 10*, in the pendulum block 7 as clearlyillustrated, and the opposite end of this spring 10 is connected to a cord 11 or other suitable means which is adapted to pass around or adjacent the pin 12. This cord or other suitable securing means is secured to the support 3 as illustrated in Fig. 3 of the drawings.

A plunger pin 13 extends through the casing 56 as illustrated clearly in Fig. 8 and is provided with an operating knob 14 upon the outer.end thereof. The inner end of this pin 13 is secured to the swivel block 4 as illustrated in Fig. 1 of the drawings, which block carries the magnet spools 2. It should be understood that by means of the plunger rod 13 the magnetic spools 2 may be pulled away from the armature plate 8 to decrease the speed of the pendulum 7 when so desired. It should be further understood that by a suitable operation of the plunger pin 13, the magnet spools 2 may be brought close to the pendulum to increase the speed of the pendulum block 7 thereby permitting the rapidity of the automatic dots to be instantly increased or decreased at the will of the operator.

It should be understood that by moving the magnets 2 to change the speed, the retractile spring 10 which is attached to the pendulum 7 as clearly illustrated in Fig. 1 of the drawings and which is secured at its opposite end to the cord 11 passing around the pin 12 as previously described, will be correspondingly weakened when the magnets are moved out for decreasing 'the speed or reducing the magnetic power of the magnets upon the pendulum 7. It should be further understood that as the magnets are moved toward the pendulum 7 for securing a greater speed or power, the spring 10 will be correspondingly strengthened, thus adjusting'itself according to the position in which the magnets are placed with respect to the pendulum 7. As clearly illustrated in Fig. 4 of the drawings it will be seen that the pins 15 and 16 are carried by the pendulum block 7 and the forward ends of these pins 15 and 16 project out horizontally, the outer extremities of these pins being bent laterally so as to form an efficient contact with the free ends of the contact plates 17 and 18 at each vibration of the pendulum 7. The opposite end of the contact plates 17 and 18 are fixedly secured to the blocks 19 and 20' by means of the rivets 21-see Fig. 4. A pin 22 is carried by the base 1 and extends upwardly through the blocks 19 and 20, the blocks being held in spaced relation by means of an intermediate washer 23. A knurled nut 22 is threaded upon the upper end of the pin 22 as clearly illustrated in Fig. 4 of the drawings for securely holding the blocks 19 and 20 which carry the contact plates 17 and 18 against accidental displacement from the base 1.

It should be understood as clearly illustrated that a wire 24 connects the contact pin 15 with a local dry battery, which dry battery is adapted to send current to the contact plate 17 thence over the wire 25 leading to the contact plate 26 upon the key lever 27. A contact pin 28 which is adjacent the plate 26 upon the key 27 is placed in a convenient manner so as to make contact with the plate 26 when the key lever 27 is moved to the right by means of the right hand.

} A wire 29 leading from the contact pin 28 passes below the base 1 when in its normal position and up to the magnet spools 2, thence over the wire 30 to the local battery, thus completing the circuit. The key lever 27 is provided with a hard rubber head or button 31 which is secured at its outer end and may be made of any form, construction or material tosuit the convenience of the operator for an elficient grip. The opposite end of the key lever 27 is provided with a pin or axis 32 upon which the key lever 27 is pivotally mounted for horizontal movement.

The key bar 27 is normally maintained in i a central or neutral position by fiat elongated springs 33, which springs are secured to the outer end of the key bar 27 by means of the rivet 34. These springs 33 extend horizontally toward the forward end of the casing and upon each side of the key bar 27 and have their free ends slightly con caved and confined within the upstanding ends of the U-shaped plate 35 secured to the under side of the key bar 27. Special attention is invited to Fig. 5 in connection with the present description. Set screws 37 are mounted in the upstanding legs of the U- shaped plate 36 and are adapted to adjust the flat springs 33 for normally holding the key bar 27 in its neutral position.-

A U-shaped plate 38 is secured to the base 1 and is provided with a plural of upstanding legs which project upon opposite sides of the key bar 27, and these upstanding legs are provided with contact screws 39 and 40 having platinum contact points 41 and 42. Contact plates 43 which are secured to the key bar 27 are disposed intermediate the contact points 41 and 42 and are connected v circuit connections with the main line.

to a wire 44 which passes through an aperture 45 in the base 1 and runs below the base passing up through the aperture 46 formed in the base 1 to a pin or rivet 21 making a contact or connection with the contact plate 18. A wire 47 is connected with the contact pin 15 of the pendulum block 7 and from this contact pin 15 passes to the main line see diagram in Fig. 10. A main line wire 48 passes through the aperture 49 and runs below the base 1, and this wire makes contact with the U-shaped plate 38 from below, thus completing the main line circuit.

In following the direction of the circuits as used in the present transmitter, attention is particularly invited to the diagrammatic views in Figs. 9 and 10. Fig. 9 shows the circuit connections with the local battery for operating the pendulum in producing automatic dots, whereas Fig. 10 shows the It should be understood that two independent circuits are used the local circuit 9 being always insulated from the main line circuit 10.

In moving the key bar 27 from its neutral position toward the right by means of the right hand, contact will be made at the contact point 28, thus closing the circuit between the magnet spools 2 and the battery 50. It, of course, should be understood that the circuit between the pin 16 and the contact plate 17 is always in a closed position, being held in this position by means of the retractile spring attached to the pendulum block 7 until the circuit through the magnet spool 2 is closed, whereupon the attraction of the magnets 2 on the armature plate 8 will draw the pendulum 7 toward the mag-. nets. The contact pin 16 carried by the pendulum 7 will be moved away from the contact plate 17 on account of the pivot pin 6 being placed between the armature plate 8 and the contact pin 16. When the pendulum 7 has been pulled toward the mag nets 2 to a certain point, the circuit connection between the contact pin 16 and the plate 17 will be broken, thus breaking the circuit to the magnets 2 and allowing the retractile spring 10 to move the pendulum to its opposite position, whereupon the contact will again be made with the pin 16 and plate 17. It should be understood that the local circuit 9 will cause the pendulum 7 to vibrate upon its axis 6 as long as the key bar 7 is held in engagement with the contact point 28. The main line circuit as shown in the diagrammatic view in Fig. 10 which is connected to the pin 15 in the pen dulum 7 will be caused to make and break a circuit between the pin 15 and plate 18 as long as the pendulum 7 is caused to vibrate by the local circuit indicated in detail in Fig. 9 and automatic dots will, therefore, be sent out on the main line. It will be seen that when the circuit is closed at 28 for operating the pendulum, the circuit at 42 will also be closed, thus allowing the automatic dots made by the vibration of the pendlum to follow the Wire 44 through the contact plate 43 and point 42 and out on the main line 48.

Dashes are made by moving the key bar 27 to the left by means of the right hand, thereby making contact only with the contact pin 41 which will break the main line circuit from the points 44 and 48 at the will of the operator in the same manner as the usual Morse key. It will be seen that by disregarding the local circuit, dots or dashes may be made by making contact with the key at 41 or 42 in the same manner as these dots or dashes are made with the Morse key now commonly in use. Therefore, the local circuit has for its object to cause the dots to be made automatically on the main line circuit.

A wire 51 is secured to the screw 52 011 the block 19, and this wire 51 has a bumper or stop 53 adapted to swing in the path of movement of the pendulum counterweight arm 7 a so as to limit the stroke of the pendulum. This structure is' shown clearly in Fig. 2 of the drawings. By moving the bumper 53 inwardly, the travel of the pendulum will be shortened, thus making the contact by the pin 15 of a shorter duration, thereby producing light dots. By moving the bumper 53 outwardly, thereby giving the pendulum a larger swing, the contact between the pin 15 and plate 18 will be of' longer duration, thus giving a longer or firmer dot. In adjusting the bumper 53, the pin 12 carrying the retractile spring 10 must also be adjusted by being pulled outwardly or pushed inwardly so that the pen dulum arm 7 will just form a contact or touch the bumper when in a neutral position, that is to say, when the same is not vibrating. The base 1 is provided with a plurality of round headed pins 54 upon the bottom thereof for the purpose of raising the base sufliciently above a support to permit the circuit connecting wires to pass freely under the base and the bottom of the box as shown in Fig. 8 which is adapted to contain the mechanism. This boX 8 is adapted, as stated, to contain the mechanism and one-dry battery cell and is constructed symmetrically so that its upper half or cover 55 which is secured to the lower half 56 are duplicates. This structure is illustrated clearly in Fig. 8 of the drawings. An aperture 57 is cut equally in each half of the box as shown in Fig. 8 adjacent the adjoining edges thereof for permitting the key bar 27 to extend therethrough in order that the key bar may be efiiciently operated by the operator of the device. A key closing lever 58 is pivota ly secured. t the .con

necting screw 59 and is adapted to be swung upwardly as shown in dotted lines so as to close and hold the key bar 27 in contact with the main circuit, thus insuring a closed circuit with the main line when the operator is not using the key.

A simple and efficient catch 60 is provided to lock the two halves of the box as shown in Fig. 8 together, and it should be understood that the knob 1a and pin 13 project through the lower section 56 so as to be conveniently accessible to the operator of the device. Suitable corner pads 61 are placed under the corners of the box as indicated in Fig. 8, and are preferably made of rubber to prevent the box from being easily moved on the table when the operating key 27 is being manipulated.

It should be understood that in view of the fact that the mechanism contained within the box illustrated in Fig. 8 is in perfect balance, the box may be placed on either side or in any position without interfering with the proper working of the pendulum 7. By inverting the box, thus reversing the mechanism, the device may be adapted for use by a left hand operator when so desired.

In providing for th adjustment of several parts of the mechanism it will be seen that the contact plates 17 and 18 may be swung upwardly or downwardly so as to be placed in the proper position for contact with the pins 15 and 16. The pins 15 and 16 may also be moved inwardly or outwardly with respect to the pendulum block 7 so as to allow the proper adjustment of the device at this point.

It should be understood that the nut 22 may be loosened or tightened according to the desire of the operator for the purpose of adjusting the blocks 19 and 20, and it should be understood that after the blocks are thus adjusted the same may be firmly held in this position by tightening the nut 22 upon the pin 22.

Attention is invited to Fig. 7 of the drawings for it will be seen that the cores 9 of the spools 2 are provided with insulating strips 62 which prevent the armature plate 8 from becoming magnetized by making contact with the cores 9.

It should be understood that the automatic feature of this transmitter depends primarily upon a pendulum actuated by the electro-magnets, wherein the magnet and dry cell are located in a local circuit confined to the box in which the mechanism of the transmitter is placed.

The minimum speed of a telegraphic transmitter is about six dots per second, and it will, therefore, be seen that a pendulum one quarter of an inch long from its point of suspension to its center of gravity according to theory and investigation will make twelve and a half vibrations per second or six and one quarter dots, since it requires two vibrations for each dot.

Having thus described the invention what is claimed as new, is

1. Inatelegraphic transmitter comprising a support, a pendulum balanced upon said "support, an armature plate secured to said pendulum, electro-magnetic means pivotally mounted adjacent to said armature plate, means for moving said electro-magnetic means toward and away from said pendulum, means for supplying an electrical current to said electro-magnetic means, and a key for closing the circuit through said electro-magnetic means.

2. In a telegraphic transmitter, the combination with a pendulum, an armature plate therefor, an electro-magnet adapted to engage the armature, and a retractile spring for said pendulum and armature, means for varying the distance between said electromagnet and armature for controlling the speed of the pendulum, a key, electrical connections leading from the source of supply through said key to said electro-magnet for operating said pendulum in making automatic dots, electrical connection leading to said pendulum and through said key for receiving the automatic dots so made by the vibrating of the pendulum, said second mentioned electrical connection being entirely independent of first mentioned connections and insulated therefrom, for the purpose set forth.

3. In a telegraphic transmitter, the combination with a key comprising a lever and contact plates on the opposite sides thereof, the key lever capable of two movements from its normal position, one of which makes contact with a local circuit and main line circuit, each independent of the other, while the other brings it in contact with the main line only, a pivoted pendulum, an armature therefor, an electro-magnet adapted to engage the armature, a retractile spring for said pendulum and armature, electrical connection comprising said local circuit leading from a source of supply to said pendulum and from said pendulum through said key bar to the electro-magnet for operating said pendulum in producing automatic dots, electrical connection independent of first mentioned connection, leading to said pendulum and through said key bar and out to the main line for receiving the automatic dots so made by the vibrating of the pendulum, and electrical connection with said key bar for the transmission of dashes to the main line said connection being entirely independent of first mentioned electrical connection, for the purpose set forth.

and armature plate carried by said pendusaid armature, a retractile spring for said pendulum and armature plate, means for varying the distance between the electro-magnet and armature plate for controlling the speed of the pendulum, electrical connection to one of said contact pins carried by the pendulum, said pin adapted to make and break a circuit between the source of supply and the said electro-magnet for operating the pendulum, electrical connection to the other contact pin carried by said pendulum and adapted to make and break a circuit on the main line when the pendulum is vibrating and send dots out on the line, a key bar having contact plates on the opposite sides thereof, said key bar capable of two movements from its neutral position, flat elongated springs on the opposite sides of said key bar having one of their ends secured thereto, their free ends extending horizontally forward, a U plate carried by said key bar, said flat elongated springs having their free ends confined within said U plate, a U-plate secured to a base and having upstanding legs on the opposite sides of the key bar, said second mentioned U-plate being adjacent to first mentioned U-plate and independent therewith, set screws carried by second mentioned U-plate adapted to engage said elongated fiat springs for normally holding said key bar in a neutral position, electrical connection with said contact plates on the key bar for making contact with connection leading to said electro-magnet and electrical connections to contact plates on said key bar for sending dots and dashes, said two connections being independent and insulated from one another for the purpose set forth.

5. In a telegraphic transmitter, the combination of a pivoted pendulum, an armature plate therefor, an electro-magnet adjustably mounted to engage said armature plate, means for adjusting said electro-magnet in relation to said armature for the purpose of increasing or decreasing the speed of the pendulum, an automatically adjustingretractile spring for said pendulum and armature plate, two contact pins carried by said pendulum and adapted to make and break a circuit when the pendulum is Vibrating, a plurality of supporting blocks, contact plates carried by said supporting blocks, said contact plates having their free ends adapted to make and break a circuit with said contact pins carried by the pendulum, means for limiting the stroke of the pendulum for adjusting for the intensity of the dot, a key comprising a lever and contact plates on the opposite sides thereof, the key lever capable of two movements from its neutral position, one of which makes contact with a local circuit for magnetizing said electro-magnet for operating said pendulum and simultaneously with a circuit making connection with the main line for the transmission of the automatic dots, the other for making contact with the main line circuit only for the sending of dashes, said main line circuit and local circuit being entirely independent of each other, for the purpose set forth.

6. In a telegraphic transmitter, the combination of a pivoted pendulum, an armature plate secured thereto, an electro-magnet adjustably mounted and adapted to engage said armature plate, means for moving said electro-magnet to. vary the distance between said electro-magnet and armature plate, an automatically adjusting retractile spring for said pendulum and armature plate, two contact pins carried by said pendulum, electrical connections-t0 said pins, a plurality of supporting blocks, a plurality of contact plates carried by said supporting blocks, said contact plates adapted to make and break a circuit between said contact pins carried by said pendulum when the latter is caused to vibrate upon its axis, a bumper pivotally mounted upon one of said supporting blocks, a counterbalancing arm carried by said pendulum, said bumper adapted to limit the stroke of said counterbalancing arm and pendulum for the purpose of adjusting for the intensity of automatic dot, a key comprising a lever and contact plates on the opposite sides thereof, the key lever capable of two movements for making circuit connections between a source of supply and the said electro-magnet for operating the pendulum, and circuit connection between main line connections for the sending of dots and dashes, said two circuits being entirely independent and insulated therefrom, for the purpose set forth.

7. In a telegraphic transmitter, the combination with a pendulum, an armature plate therefor, and an electro-magnet adapted to engage the said armature, means for insulating said armature from contacting with the cores of the electro-magnet, means for adjusting said electro-magnet in relation to said armature, a key lever mounted upon a base and contact plates on the opposite sides thereof, two independent circuits adapted to pass through said contact plates and key lever, one of said circuits being local and adapted to magnetize said electro-magnet for operating said pendulum, the other for sending dots or dashes to the main line, a box adapted to contain the mechanism of the said transmitter and one cell of dry battery,

an aperture in a side of the said box adapted to allow the said key lever to project out for operating, means projecting out of said box whereby said electro-magnet may be adjusted in relation to said armature plate without opening said box, a key closing lever secured to the side of the said box and adapted to be swung up against said key lever for closing and holding the key lever in contact with the main line, said box with mechanism of transmitter contained therein adapted to rest on HENRY J. MAHONY.

one face or turned upside down and rest on Witnesses: its opposite face thereby reversing the mech- WVM. DRIsooLL, anism and adapting itself for the use of a Jew. P. HOGAN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

